The noodles in Shanghai fried noodles, or cu chao mian, are thick, chewy and wheaty, and they give the simply seasoned stir-fry much of its appeal. Japanese udon is similar in appearance and texture, and since it’s easier to find in dried form in supermarkets, it’s what we call for in our version of the dish. There is no sauce to speak of in this stir-fry—the noodles absorb the flavorings and in doing so take on a brownish hue. We admit to cheating a little by adding oyster sauce—not a typical ingredient in Shanghai fried noodles—as it brings some sweetness along with loads of umami. The balsamic vinegar may also seem like an odd ingredient, but it’s a great stand-in for malty, subtly sweet Chinese black vinegar that’s made from rice. The vinegar’s acidity nicely balances the deep, savory notes in the dish.